Around 2.3 billion people globally rely on biomass for cooking, contributing to severe health, environmental, and climate challenges, with household air pollution responsible for over 4 million deaths each year. This widespread dependence underscores the urgent need for accurate measurement of biomass consumption and associated emissions. The primary objective of this study is to enhance the understanding of household biomass energy use by quantifying the contributions of woody biomass and crop residues, examining seasonal consumption patterns, and estimating the resultant CO₂e emissions. The study’s novelty lies in its application of a digital, sensor-based system to continuously and accurately monitor biomass consumption across 420 households in Eastern Rwanda, conducted over three agricultural seasons. This approach generates high-resolution, region-specific data on the utilization of firewood, crop residues, and charcoal, while directly linking consumption patterns to CO₂e emissions. The findings indicate that firewood accounts for 86% of the total biomass used for cooking, followed by crop residues at 13% and charcoal at 0.8%. The estimated daily household consumption amounts to 3.1 kg of firewood, 0.47 kg of crop residues, and 0.03 kg of charcoal. The relatively high amount of crop residue suggests a chronic shortage of firewood, despite the intensive tree-planting campaigns. Firewood consumption remained stable during season A (short rainy) and season B (rainy), with a slight decrease in season C (dry). Crop residues decreased steadily from Season A to B, and further to C. The estimated annual CO2e emission from biomass combustion is 1.32 tons per household and 0.48 tons per capita. Digital methods provide precise, time-resolved data on fuel types and consumption, offering valuable insights for energy planning and carbon financing. Future research should integrate PM₂.₅ emissions to better assess health impacts and determine the sustainable balance between using crop residues as fuel and returning them to the soil.
Tag: crop residues
Farmer information brief on the fodder value chain: Transformation of livelihoods and ecosystems through nature-based enterprises in Eastern Province, Rwanda
Key highlights
- Planting improved fodder varieties (Napier, Brachiaria, Chloris gayana, fodder trees, legumes) can boost nutrition and milk yields.
- Mixing grasses, trees and crop residues (maize, beans, rice straw) can provide year-round feed, especially in dry seasons.
- Applying good management practices means proper land preparation, timely planting, manure use, regular weeding, and harvesting at the right stage.
- Investing in improved fodder is important: one hectare can feed 15 dairy cows, raise milk output and deliver strong profits.
- Climate resilience and livelihoods can be strengthened by reducing feed gaps, improving animal health, increasing manure for crops, creating jobs, and using tree-based systems to adapt to climate change.
Early-stage sustainability assessment of greywater treatment with Moringa oleifera seed extract and biochar
Access to safe and reliable water remains a significant challenge in much of the Global South, especially in rural areas where greywater treatment infrastructure is lacking. This study presents an early-stage sustainability assessment of a novel system that utilises biochar and Moringa oleifera seed extracts to treat greywater in rural Kenyan households. The proposed solution combines local biochar, a by-product of wood gasification cookstoves, and powdered Moringa oleifera seed cake, a residue from local agroforestry activities. The presented assessment applied a qualitative approach that integrates life cycle, circular bioeconomy, and sustainable sanitation principles. The key sustainability opportunities involved in the assessed system include improved human health and hygiene, the carbon sequestration potential of biochar, greywater reuse, and efficient use of local biomass resources. However, the system also involves risks related to filter media disposal, nutrient loss and system maintenance. The analysis highlights the trade-offs between using Moringa oleifera seed cake for water purification and animal feed. Moreover, the early-stage assessment identifies the need for pilot trials, participatory design and data collection to develop future life cycle analyses and implementation strategies. This integrated approach provides a sound basis for the sustainable development of natural greywater treatment systems that meet the goals of a circular bioeconomy.
Fallow and sesbania effects on response of transplanted lowland rice to urea
Although lowland soils in Asia are frequently fallowed between rice (Oryza sativa L.) crops, little is known about the effects of fallow management on N cycling and growth of a subsequent lowland rice crop. A 2-yr field study was conducted in the Philippines on a Typic Tropaquept to determine the interactive effects of pre-rice land management and urea fertilization on rice growth, N uptake, and response to applied N. Management treatments before transplanting wet-season rice were (i) weedy fallow (WF), (ii) weed-free fallow (WFF), and (iii) Sesbania rostrata Bremek. & Oberm. grown in situ for either 45 or 60 d as green manure (SR). Weeds and S. rostrata were incorporated after soil flooding on 23 June of each year, and rice was transplanted on 30 June 1989 and 4 July 1990. Four rates of urea-N (0, 40, 80, and 120 kg N ha1) were applied to rice following each pre-rice treatment. The efficiency of added N with respect to dry matter accumulation (kg dry wt. kg1 N applied) was reduced following WF and SR compared with that following WFF at 45 d after transplanting (DAT), about 10 to 15 d after panicle initiation. Rice recovered from the initial adverse effect of incorporated plant residue, and growth rate after 45 DAT was greater following SR and WF than that following WFF. Grain yield without applied urea was 0.9 Mg ha1 higher following WF than that following WFF. Incorporated weed-N (35 kg N ha1) substituted for 40 kg urea-N ha1. High initial rice growth rate in the absence of incorporated plant residue (WFF) resulted in a lower rice N concentration at 45 DAT. Incorporated S. rostrata and weeds continued to provide N to rice after 45 DAT. When no plant residues were incorporated (WFF), the application of only one-third of the total urea-N at panicle initiation was insufficient to meet the N requirements of rice. Basal urea-N (two-thirds of the total urea-N) failed to increase rice dry weight or N concentration at 21 DAT following all pre-rice treatments. Results suggest that optimal distribution of urea among application timings might depend on whether plant residues are incorporated before transplanting.
Balancing livestock free grazing and ecosystem functionality: investigating the carrying capacity of grazing land in the Eastern Savannah of Rwanda
This study focused on investigating the carrying capacity of individual grazing lands in the Eastern Province of Rwanda. We collected data on above-ground biomass of natural pasture from 63 farms during the wet and dry seasons to capture the seasonal variation of forages. Since the grazing system is based on individual farms, we clustered farm size into three clusters, namely ≤ 10.9 ha (small); 11–20.9 ha (medium) and ≥ 21 ha (large). Dry matter and chemical composition of biomass samples was determined. Additionally, as crop residues are a significant feed resource for farmers, we also estimated their production for the year 2023 because of the availability of reliable data over the corresponding two agricultural seasons. Dry matter exhibited significant difference (p < 0.0001) across both farm sizes and seasons. Similarly, crude protein showed significant difference (p < 0.0001) across farm sizes and seasons. The neutral detergent fibre (NDF) showed only significant difference across the seasons (p < 0.0001). Acid detergent fibre (ADF) showed significant difference (p < 0.05) across both farm sizes and seasons. The interaction between farm size and season was significant difference (p < 0.0001) for NDF and ADF (p = 0.0085). Furthermore, the tropical Livestock Unit (TLU), showed that the available biomass in the medium farm could feed only the TLU for a period of 58 days while the small farm could only feed for 42 days whilst the crop residues could meet the dry matter intake of 171,750 TLU annually. The findings suggest the effective crop residue utilization and highlight that proper grazing land management strategies should be applied for optimizing cattle productivity, ensuring sustainability, and climate resilience.
Greenhouse gas emissions from natural ecosystems and agricultural lands in sub-Saharan Africa: Synthesis of available data and suggestions for further research
This paper summarizes currently available data on greenhouse gas (GHG) emissions from African natural ecosystems and agricultural lands. The available data are used to synthesize current understanding of the drivers of change in GHG emissions, outline the knowledge gaps, and suggest future directions and strategies for GHG emission research. GHG emission data were collected from 75 studies conducted in 22 countries (n=244) in sub-Saharan Africa (SSA). Carbon dioxide (CO2) emissions were by far the largest contributor to GHG emissions and global warming potential (GWP) in SSA natural terrestrial systems. CO2 emissions ranged from 3.3 to 57.0MgCO2ha1yr1, methane (CH4) emissions ranged from g-4.8 to 3.5kgha1yr1 (g-0.16 to 0.12MgCO2 equivalent (eq.)ha1yr1), and nitrous oxide (N2O) emissions ranged from g-0.1 to 13.7kgha1yr1 (g-0.03 to 4.1MgCO2 eq.ha1yr1). Soil physical and chemical properties, rewetting, vegetation type, forest management, and land-use changes were all found to be important factors affecting soil GHG emissions from natural terrestrial systems. In aquatic systems, CO2 was the largest contributor to total GHG emissions, ranging from 5.7 to 232.0MgCO2ha1yr1, followed by g-26.3 to 2741.9kgCH4ha1yr1 (g-0.89 to 93.2MgCO2 eq.ha1yr1) and 0.2 to 3.5kgN2Oha1yr1 (0.06 to 1.0MgCO2 eq.ha1yr1). Rates of all GHG emissions from aquatic systems were affected by type, location, hydrological characteristics, and water quality. In croplands, soil GHG emissions were also dominated by CO2, ranging from 1.7 to 141.2MgCO2ha1yr1, with 1.3 to 66.7kgCH4ha1yr1 (g-0.04 to 2.3MgCO2 eq.ha1yr1) and 0.05 to 112.0kgN2Oha1yr1 (0.015 to 33.4MgCO2 eq.ha1yr1). N2O emission factors (EFs) ranged from 0.01 to 4.1%. Incorporation of crop residues or manure with inorganic fertilizers invariably resulted in significant changes in GHG emissions, but results were inconsistent as the magnitude and direction of changes were differed by gas. Soil GHG emissions from vegetable gardens ranged from 73.3 to 132.0MgCO2ha1yr1 and 53.4 to 177.6kgN2Oha1yr1 (15.9 to 52.9MgCO2 eq.ha1yr1) and N2O EFs ranged from 3 to 4%. Soil CO2 and N2O emissions from agroforestry were 38.6MgCO2ha1yr1 and 0.2 to 26.7kgN2Oha1yr1 (0.06 to 8.0MgCO2 eq.ha1yr1), respectively. Improving fallow with nitrogen (N)-fixing trees led to increased CO2 and N2O emissions compared to conventional croplands. The type and quality of plant residue in the fallow is an important control on how CO2 and N2O emissions are affected. Throughout agricultural lands, N2O emissions slowly increased with N inputs below 150kgNha1yr1 and increased exponentially with N application rates up to 300kgNha1yr1. The lowest yield-scaled N2O emissions were reported with N application rates ranging between 100 and 150kgNha1. Overall, total CO2 eq. emissions from SSA natural ecosystems and agricultural lands were 56.9±12.7 × 109MgCO2 eq.yr1 with natural ecosystems and agricultural lands contributing 76.3 and 23.7%, respectively. Additional GHG emission measurements are urgently required to reduce uncertainty on annual GHG emissions from the different land uses and identify major control factors and mitigation options for low-emission development. A common strategy for addressing this data gap may include identifying priorities for data acquisition, utilizing appropriate technologies, and involving international networks and collaboration. © 2016 Author(s).
Mushroom as a means of sustainable rural development in the Chin State, Myanmar
Restricted access to quality crops and markets limits the capacity of rural communities to generate income in the mountainous regions of South and Southeast Asia, often resulting in the exploitation of forest systems, a subsequent decline in forest health, and the need for alternative means of income generation as well as forest restoration programmes. Cultivation of edible and medicinal mushrooms has been shown to be a feasible alternative source of income and also contributes to the household nutrition of rural and impoverished communities. There are a number of ongoing programmes in South and Southeast Asia currently implementing trainings and demonstrative practices for the cultivation of mushrooms at the village level. In this context, we implemented different cultivation strategies in selected rural areas in the Chin State, Myanmar. The cultivation strategies were to 1) introduce mushroom cultivation using locally sourced raw materials as substrates for rural communities unfamiliar with mushroom cultivation; and 2) improve the technical knowledge of those already experienced in mushroom cultivation in order to increase yield and minimize challenges in production systems. We introduced Pleurotus sp. cultivation to mushroom growers in the Chin state, Myanmar. These cultivation strategies will help further improve and develop mushroom industries in rural areas and contribute to rural development. In addition, we focused on cultivation systems that incorporate the use of crop residues and woody substrates in order to ensure a sustainable, integrated approach.